forked from joyang1/JavaInterview
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathCountingSort.java
More file actions
51 lines (41 loc) · 1.1 KB
/
Copy pathCountingSort.java
File metadata and controls
51 lines (41 loc) · 1.1 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
package sort;
/**
* Created by TommyYang on 2018/3/9.
*/
import java.util.Arrays;
/**
* 计数排序
*/
public class CountingSort implements IArraySort {
@Override
public int[] sort(int[] sourceArr) throws Exception {
// 对 sourceArr 进行拷贝，不改变参数内容
int[] arr = Arrays.copyOf(sourceArr, sourceArr.length);
int maxValue = getMaxValue(arr);
return countingSort(arr, maxValue);
}
private int[] countingSort(int[] arr, int maxValue) {
int bucketLen = maxValue + 1;
int[] bucket = new int[bucketLen];
for (int value : arr) {
bucket[value]++;
}
int sortedIndex = 0;
for (int j = 0; j < bucketLen; j++) {
while (bucket[j] > 0) {
arr[sortedIndex++] = j;
bucket[j]--;
}
}
return arr;
}
private int getMaxValue(int[] arr) {
int maxValue = arr[0];
for (int value : arr) {
if (maxValue < value) {
maxValue = value;
}
}
return maxValue;
}
}